Method and system for athletic motion analysis and instruction

ABSTRACT

A system and method for analyzing and improving the performance of a body motion of an animal or human subject requires instrumenting a subject with inertial sensors, monitoring a body motion of interest, converting sensor data into motion data and animation, comparing the motion data with existing data for motion related performance parameters, providing a real-time, information rich, animation and data display of the results in color coded displays; and based on the results prescribing a training regime with exercises selected from a library of standardized exercises using standardized tools and training aids.

RELATED APPLICATIONS

This application is a continuation of pending U.S. application Ser. No.11/340,088, filed Jan. 26, 2006, which claims priority to U.S.provisional application No. 60/647,751, filed Jan. 26, 2005. Each ofthese applications is herein incorporated in its entirety by reference.

STATEMENT OF GOVERNMENT INTEREST

This invention was made without the benefit of federally sponsoredresearch or development.

COPYRIGHT NOTICE

A portion of this patent application, including the figures, containsmaterial that is subject to copyright protection. Copyright notices mayor may not be included in all cases. Reproduction of this material inthe form published by a patent office in a jurisdiction in which thisapplication is filed is permitted. All other rights are reserved.

BACKGROUND OF THE INVENTION

Over the course of time, many different techniques have been implementedin order to teach the proper mechanics of various athletic motions,including swinging a golf club. Many instructors, e.g., golfprofessionals, use a video analysis system to teach a student how toproperly swing a golf club. Using a typical video analysis system, thestudent's golf swing is captured by a video-recording device. Theinstructor replays the recorded video information to illustrate thestudent's golf swing while providing feedback regarding the swing.Instructional feedback may be comments relative to problems associatedwith the student's swing, compliments regarding improvement in thestudent's swing, suggestions on correcting the user's swing, or anyother verbal instructional comments in context with the student's swing.Visualizing one's personal golf swing in this manner has been recognizedas a valuable tool in identifying problems as well as correcting thoseproblems in order to improve the overall golf swing.

Although video analysis systems are widely used by golf professionals,these systems have drawbacks. One drawback relates to having a golfprofessional subjectively analyze the video information. Not only isthis analysis subjective and therefore open to interpretation andsubject to inaccuracies, but also such analysis is exacerbated by thefact that many problems associated with a golf swing are typically notcaptured by the video recording system given different camera angles,too few cameras, or loose clothing. Therefore, golf professionals aretypically forced to guess the problem. Accordingly, the advice given bya golf professional may be inaccurate and inconsistent since it isdifficult to isolate mechanics and measurements of the swing on video.

In order to overcome the drawbacks associated with typical videoanalysis systems, instructors have adopted motion or position analysissystems as an aid to analysis and instruction. Since the 1970's,universities and private research foundations have studied human motionusing techniques that allow two-dimensional film or videotape to beprocessed into three-dimensional data. Progress had been made incharacterizing the properties of human motion (biomechanics) from thesimple measurements of displacement, velocity, and acceleration to themore complicated measurements of force and torque (stress). Although thescientific community has taken steps towards understanding human motionand its effects upon the musculosketal system, very little of thisinformation has been applied to the clinical area where a patient candirectly benefit.

Current motion analysis systems require that the student/athlete to wearsensor elements on their body and the sensor elements transmitpositional data of isolated body parts, such as hands, hips, shouldersand head. The isolated points on the body are measured during a swing inaccordance with an absolute reference system, e.g., a Cartesiancoordinate system wherein the center point is a fixed point in the room.By using motion analysis, exact measurements are provided from which aninstructor can more accurately determine problems in a student's swing.Even though motion analysis provides accurate positional data of thestudent's swing, it is not, in and of itself, particularly useful sinceit gives no visual aid as to where the problems may really be. When usedby itself, the motion analysis system is not an effective teaching toolsince the instructor is only provided with numbers and not avisualization of what the student is doing wrong. Some motion analysissystems provide animation that depicts elements of a golf swing basedupon captured data. However, the animation is crude and doesn't show thegolfer what he/she looks like during a swing.

Consequently, motion analysis systems are used with video analysissystems in order to try to overcome the problems associated with eachsystem as it is used independently of the other. The instructor may usethe motion capture data and subjectively map the information to thevideo data. Although this provides more specific data to the instructor,it is associated with at least one significant problem. The instructor,while viewing the video, must estimate the swing positions correspondingto the data points from the motion analysis information. Analysis of theswing requires not only considerable effort, but also a significantamount of estimation in associating the positional data points with anassociated position on the student's swing.

Moreover, the systems for providing the video analysis are separate fromthe systems that provide motion capture information such that theinstructor must manipulate numerous controls for displaying, to thestudent, the various positional measurement values as well as forproviding separate video replays.

With respect to golf and the golf swing, some systems have beendeveloped to respond to the needs of both the self-taught player and theprofessionally taught player. Examples of such systems are: (1) theSportech Golf Swing Analyzer and WAVI™ system both manufactured bySports Technology, Inc. of Essex, Conn.; (2) BioVision™ manufactured byOptimum Human Performance Centers, Inc. of Menlo Park, Calif.; (3) thePro Grafix System manufactured by GolfTek of Lewiston, Id.; and (4) theSwing Motion Trainer manufactured by Sport Sense of Mountain View,Calif.

Other prior art teaches, for example, a system where a golfer wears anumber of reflective tapes at various places on his or her body. Whilethe player swings the club, a TV camera captures the motion of thegolfer through the motion of the reflective tape. The image of themotion is digitized and the two-dimensional coordinates of thereflective tapes are calculated. The calculated coordinates are thenmanipulated in various ways to analyze the golfer's swing. For example,the coordinates can be used to construct a moving stick figurerepresenting the golfer's swing.

Another system discloses a video device and method which detects theclub head velocity via a colored club head and color detection unit. Theclub head velocity is then displayed in analog or digital form. A seriesof swings can then be analyzed by comparing the relative club headvelocities for different club swings.

Yet another system provides a video system which displays a live videosignal of a golfer's swinging motion for the golfer to see whileswinging. A series of video overlays can be imposed upon the videosignal for reference and analysis purposes.

There is an apparatus and method which uses a computer to produce aseries of still images from a videotape of a golfer's swing. The stillimages are then overlaid with a series of corrected images which includelines depicting proper form. The result is then augmented with furthervisual or audio information and recorded onto another tape for viewingand analysis.

A golf practice apparatus provides recording and instant playback ofvideo images of a golfer's swing. An infrared camera and flash unit areused to obtain snapshot images of the clubhead and ball just before andafter impact. An optical sensor array and processor calculatesstatistical data on club speed, ball speed, and ball angle.

What is lacking in the field is an athletic motion analysis apparatusand method which is capable of capturing and plotting the total motionof a user with sufficient data to reduce, analyze, report on, andpresent the component parts of the motion and the degree of coordinationof the component parts as feedback to the user in such a way as tooptimize his assimilation and understanding of the information; furtherto provide a comparative study of the component parts of the user'sperformance as to its own prior test results or the performance of otherpersons or other benchmark values; and further, to provide a relatedprescription of specific exercises tailored to the user's level ofperformance, areas of deficiency, and available time for improving hisor her skill level through practice of training exercises.

For example, as a golf swing is executed, the golfer rotates, amongother things, the hips, shoulders, and arms in a sequential, and yetcoordinated fashion. To maximize energy in the swing, the golfer mustsmoothly transfer energy from the feet to the hips, to the shoulders, tothe arms, and hence to the club, culminating at the time and point ofimpact with the ball. What is needed is a system and method of motioncapture and data processing with specialized software to process thisdata and generate a coordinated, multiple format presentation to theuser which will effectively demonstrate the most efficient kinetic linkbetween the golfer's motion segments, and prescribe exercises likely toimprove the user's performance.

It is with respect to these and other considerations that the presentinvention has been made.

SUMMARY OF THE INVENTIONS

A kinetic link in the context of the invention is a chain ofinterdependent components of motion acting towards a common goal, theeffective and efficient execution of the motion. This kinetic linkprinciple is applicable to all dynamic, athletic-type body motionsintended to perform work or convert or transfer energy in any manner bymeans of bodily exertion, with or without the use of a hand or footactuated or operated tool or article of sporting equipment. For example,in a golf swing motion, the process of striking a golf ball with a golfclub, the kinetic link is composed of four principle components of themotion with three links. These four components and three links incombination represent the full motion of the body. The componentsconsist of the hip segment, shoulder segment, arm segment and the club.The links include the musculature found between each body segment. Sincethe frame of reference and the point from which this type of motion mustbe leveraged is the ground itself, a complete analysis of the motionmust consider the feet first, then overall posture, then hips, thenshoulders, then arms, then club, and finally the ball. A weakness at anypoint in the kinetic link results in a less than optimal totalperformance. Means of identifying and improving the component parts ofthe motion will improve the overall performance. This assumption is atthe foundation of the present invention.

The invention, in the broadest sense, may be a global, knowledge-based,enterprise system and method for providing performance testing andtraining regimes to persons for whom athletic activities such as golfingand others for whom repetitive athletic motions are an inherent part oftheir normal work or recreational activities, for improving theeffectiveness of their golf swing or other specific athletic motion.

A typical example of the system and method uses state of the arttechnology and equipment for instrumenting a user or subject andmonitoring a motion, draws upon and contributes to a vast library ofperformance data for analysis of the test results, provides aninformation rich, graphic display of the results in multiple,synchronized formats for user viewing and/or monitoring by a coach orsystem operator, and based on the results prescribes a user-specifictraining regime with exercises selected from a library of standardizedexercises using standardized tools and training aids.

Users and their coaches may access the library of performance data tosee and compare a user's most recent test performance to its own orother testees' prior test results. After an appropriate amount ofoff-line exercising, and/or at the desire of the user or coach, thetesting is repeated. The specifics of the prescribed training arere-calculated and may include a weighted consideration of the currentperformance testing result in addition to prior test results. Theperformance reports provide an objective record of the type and degreeof changes in performance that the user has experienced.

The system may be employed during live practice sessions to provideessentially instant or “real time” visual and/or auditory biofeedback,or provide “replay” presentations, of each successive attempt at aparticular drill or a full motion. Deviations in specific parametersfrom the objectives of the prescribed drills are reported and the userhas the immediate opportunity to respond to the feedback and reduce thedeviation of the specific parameter during an immediate next attempt atthe same drill.

In one embodiment, the invention is a local system or method for golfswing motion analysis of a golfer, intended to improve the golfer'sperformance by repetitive use. The invention includes the use ofmultiple body and/or tool mounted sensors, wired or wirelesstransmission of sensor data in real time to a receiver/computer anddatabase system for data processing and analysis, along with a videoand/or audio recording input of the test. Results are instantlygenerated by the system, consisting of associated forms of biofeedbackincluding graphical representations of coordinated and comparative dataoutput on components of the full motion, along with animations of themotion generated from the motion data, and actual video of the motion.The three forms of feedback are combined in their presentation for readyassimilation and understanding by the golfer and/or instructor in eitheran immediate form to enable sequential, monitored attempts withintermediate feedback, or a later feedback mode with an extended periodfor practice of prescribed drills intended to improve aspects of themotion.

The analysis reduces the full motion to predetermined major componentmotions. The coordinated data output portion of the results mayrepresent the relative timing and amplitude of components of the user'sown motion. The comparative data output may represent a comparison ofthe relative timing and amplitude of components of the user's motion tothe same components of an expert or other standard performance data fromthe system database, or the user's own prior test performance data. Thedata processing and biofeedback may further include prescriptions from adatabase of standard exercises, tailored according to the user's levelof performance and time available, for training on a component-of-motionbasis, such as stance, balance, hip motion, and shoulder and arm motion,adjusted according to the user's actual performance data. The exercisesmay prescribe or presume the use of specialized tools and training aidsfrom among a library of pre-determined tools and training aids, duringthe exercises.

As described above, the data input, analysis, and the biofeedback reportis preferably augmented by use of video, audio, and other recordingdevices emplaced and focused to capture additional motion data at adesired direction from the user under test, and processed to provideadditional graphical, video, audio or other form of output that can beintegrated with the data output for optimal user understanding andassimilation of the analysis and report.

The system and method in local or global embodiments may be applied toother athletic or occupational motions by which energy is transformedthrough user motion into work of any type, for improving performance,preventing injury and/or providing a rehabilitation program.

A set of inertial motion sensors are attachable to the user's body,and/or motion tool or device such as a golf club, at strategic points bythe use of specially designed appliances. Each motion sensor contains amulti-element sensing system and circuitry for sensing and reportingthree dimensional position and attitude of the sensor, transmitting areal time output of vector data for further application-specificprocessing. One embodiment of the multi-element sensing system withinthe motion sensor includes three gyroscopic inertial sensors, threeaccelerometers, and three magnometers, as is produced by InterSenseInc., of Bedford, Mass. Motion data is typically updated at a rate of120 Hertz from a system employing three motion sensors, although systemswith fewer and more motion sensors and with faster and slower positionupdate rates are within the scope of the invention.

The vector data from the full set of motion sensors is sufficient datafrom which to derive and characterize the principle components of a golfswing or other athletic motion, as is further described below. Theinformation is transmitted in near real time directly from each sensorindividually, or via a common transmitter to which some or all thesensors may be hard wired, to a nearby receiver and hence to aprocessing computer for application-specific data processing andanalysis, and generation of data and graphical output reportsrepresenting the user's performance, as is further described below.

The processing computer can perform relational calculations on the datareceived from the various sensors, thereby allowing computation ofvarious application-related parameters of interest. As an example, theprocessing computer with its golf-specific software can calculateclub-face angle or the angle through which the golfer turns his or hershoulders while swinging the golf club. Such parameters are referred tohere as “performance parameters.”

In a golf swing motion analysis system in particular, inertial sensordata is typically processed into the following parameters relating tothe golfer's body performance: hip velocity (degrees per second); hiprotation (degrees negative and positive); shoulder velocity (degrees persecond); shoulder rotation (degrees negative and positive); club release(degrees per second); club speed (miles per hour); club face rotation(degrees open/closed); club path (degrees inside or outside of club'saddress position); hip linear movement (centimeters left or right ofneutral address); hip shoulder separation (time difference betweenmaximum hip, shoulder, and club velocity); flexion/extension of hipsegment (centimeters traveled along z-axis); and kinetic link. Theseparameters are further extrapolated to yield a predicted “ball inflight” resulting performance of parameters: spin (degrees per second);launch angle (degrees); carry distance; roll distance (yards); totaldistance (yards); distance traveled off line (yards right or left); ballflight character (fade, draw, hook, slice, push, pull, straight); andPTI or power transfer index.

The processing computer can also display information about the swingthat will allow the golfer or his instructor to visualize and adjust theswing. For example, in one aspect, the system displays live video feedof the golfer (obtained through a video feed from a video cameracritically positioned adjacent to the golfer and coupled wirelessly orotherwise to the processing computer), an animated simplification of thesame motion generated from motion data, and statistics reporting thestate of the various parameters in any given freeze-frame. The systemcan also display the results of the various calculations of performanceparameters, as described in the previous paragraph, which characterizethe swing over time; for example, the system can display data regardingthe club-face angle or the angle through which the shoulders rotateduring a particular swing.

A system interface between the processing computer and the golfer in theform of a control or feedback module mounted on or near the instrumentedgolfer can provide instructions to the golfer in preparation for or inresponse to a particular attempted golf swing. The system interface mayinstruct the golfer, for example, to address the ball, give afive-second window for the golfer to initiate a swing, etc. Suchinstructions may in one embodiment be in the form of audible beeps, orsynthetic speech or pre-recorded voice commands. Colored lamps or abacklit LCD or other type visual signal display can also issue coded oralphanumeric instructions. Such functions are useful in securingspecific and timely inputs needed to calibrate the sensors for absoluteposition, as well as to coordinate the orderly sequencing or progress ofa testing session.

In one response mode, the system can be characterized as operating in a“biofeedback mode,” where the processing computer through the systeminterface assists the golfer in following prescribed exercises(described in more detail below). In that mode, the processing computercan also display on its display unit or screen, to the golfer and/or hisinstructor, one or more calculated performance parameters and videoimages of the golfer. Calculated diagnostic parameters of interest canbe reported on the screen, stored for later analysis, or converted intosuccess or failure codes, which can be transmitted back to the golferand/or his instructor, or any combination of those actions.

Codes transmitted as biofeedback to the golfer may be in the form of atone or a color that differs between a successful swing and anunsuccessful swing. For example, if the system is programmed and set upfor training the golfer in a set of exercises where the golfer tries torotate the shoulders through exactly 40 degrees from vertical, thesystem, as through a control module, can alert the golfer through tonesor lights or changing colors within the graphic display screen when theswing differs from the ideal rotation angle by more than a predeterminederror. For example, only if the rotation angle falls between 35-45degrees, will the swing be considered a success. The tones or changinglights may have several bands or ranges, allowing intermediate or scaledresults. For example, a red light might follow a swing in which adiagnostic parameter badly diverged from ideal, a yellow light mightfollow a swing in which the same diagnostic parameter only somewhatdiverged from ideal, and a green light might follow a swing in which thesame diagnostic parameter diverged from ideal by less than thepre-assigned margin of error. The signal light may be the backgroundcolor of an animation. The information conveyed by the changing color ofthe selected illuminated portion of a screen may be likewise presentedwith same or more or less detail in other audio, textual, numericaland/or graphical formats, including numbers, bar graphs, line graphs andtext messages. Oral callouts may be used in combination or in thealternative.

The feedback report may also be continuous or highly differentiated; forexample, the length of an audible tone might correspond to the extent towhich the diagnostic parameter diverged from ideal, and the golfer isinstructed to practice until the tone shortens or disappears. The numberof blinks of a light, light color, sound frequency, sound volume, tonelength, and tone type are among the characteristics that can be used inthe feedback mode. The audio format feedback information can be producedwith synthesized voice output from a speaker or earphones.

The processing computer and system interface also can include monitoringby a golf professional or other motion expert or instructor, directly orremotely as through an internet connection, and allow him or her totransmit to the golfer instructions to initiate, cease, or controlexercises through instructor command inputs to the system, or receivedby the system from a remote location, such as through an internetconnection.

After computation of the various golf-related parameters of interest,those diagnostic parameters can be utilized by indexing a crossreference table of test results and exercises to automatically prescribeto the golfer an assignment of appropriate individualized exercises toimprove his or her swing. In a one embodiment, each calculateddiagnostic parameter is divided into two, three, or more ranges, witheach range corresponding to a prescribed action with respect to aparticular exercise. For example, a first range for a particulardiagnostic parameter can result in a prescription of a certain exercise,a second range of the same parameter can result in a differentprescription, and a third range of the same parameter can result in noprescribed exercise because the golfer does not have a problem with theparticular aspect of the swing that the parameter measures. Thedifferent prescription in each example can be, for example, a specificdifferent number of repetitions of a given exercise, a differentpriority level given to a given exercise (see next paragraph forpriority levels), a different exercise tool or accessory being used fora given exercise, or an entirely different exercise. Further, thefrequency and duration of the exercises may be apportioned by theprescription compiler in accordance with the golfer's available time andschedule, as it was previously inputted to the system by the golfer.

Alternatively, the prescriptions may result from combinations of resultsfrom two or more diagnostic parameters. In variations, the knowledgebase may include rules developed through expert interviews, automatedanalysis techniques based on measured results produced by the swing, orprinciples of fuzzy logic. In one embodiment, the diagnostic parametersproduce exercise prescriptions with assigned priority levels. Forexample, if a particular golfer's swing produces one diagnosticparameter that is very far from ideal while other diagnostic parametersdiverge from ideal only partly, the first diagnostic parameter will beassigned a higher priority level than the others. For another example,if two diagnostic parameters diverge from ideal but one is consideredmore important to a good golf swing or alternatively one is consideredimportant to control to provide a good foundation for the other, thenthat one will be assigned a higher priority level than the other.

In one embodiment, each prescribed training exercise is assigned apriority level from one to nine, and several exercises may be assigned acommon priority level. In that embodiment, the golfer or the instructorcan indicate by input to the computer how much time the golfer hasavailable to perform the exercises, and based on that information, thesystem can recommend which ones to perform. For example, if an athleticmotion analysis system projects a need for three exercises with apriority level of one, five exercises given priority level two, and fourother exercises with higher priorities, and if each exercise has beendetermined to require at least fifteen minutes to perform for reasonableeffectiveness, and the golfer has a limited time for exercise, then thesystem might assign or prescribe accordingly. As specific examples, ifthe golfer indicates that he has one hour available, the assignment maybe performing only the three priority one exercises for twenty minuteseach. If the golfer has two hours available, the system might prescribeperforming all priority one and all priority two exercises for fifteenminutes each. If the golfer has three hours available, the system mightassign all exercises for fifteen minutes each. The minimum times toperform each different exercise might vary, the time recommended toperform any particular exercise might vary or be fixed, and thegradations of priority can be changed as desired.

The diagnostic parameters can also or alternatively be used toprescribe, select or fit golf equipment to the golfer, such as golfclubs or golf shoes from among one of several types or customizedversions having particular measured parameters. For example, the length,lie angle, loft, or weight of a particular type of golf club can beselected based on analysis of the diagnostic parameters calculated forthe golfer, preferably in combination with parameters about the golfer,such as his or her height, hand length, and foot size.

In another aspect, parameters calculated at time of impact, such asposition and orientation of the club face relative to the ball andvelocity vector and face angle of the club, can be used to predict theforces on the ball and thus predict its trajectory. Knowledge of theterrain can allow determination of the distance and path of the struckgolf ball, or alternatively the calculation can predict distanceassuming the terrain is flat. Such predictions based purely on forcecalculations can be supplemented with information about the behavior ofthe ball in atmosphere, such as through testing of particular types ofgolf balls, to adjust for air resistance. In a further variation, winddirection and velocity can be taken into account, with such data inputinto the system manually or through an electronic anemometer or localair data station coupled to the system electrically, or via an internetor wireless connection.

The system may be remotely or locally controlled so that an off-site oron-site instructor may direct the operation of the system or monitor theresults. In a purely user-contained mode, control inputs for set up andtesting operations may be entered, test exercises performed, and swingdata viewed and reviewed by a user with the aid of a personal controlmodule and data monitoring system such as a belt-worn control/displayunit or module.

The methodology and the system are applicable to other repetitiveathletic and occupational motions for testing of animals or humans,analysis, reporting, diagnostic review by coaches, trainers and/ormedical personnel or physical therapists, with prescriptions beingsimilarly generated for training to improve performance, prevent injury,or for rehabilitation of various motion capabilities where the motion issusceptible of data collection and reduction into component parts in themanner described above, and the report can be presented in asynchronized, composite display of animation, multiple data tracks andvideo format.

It is an additional goal that the report and the prescribed regime ofpractice drills can be taken home as a recording in any useful format,or accessed from home through a browser-based, on-line access pointconnecting to the local system or to a host, knowledge-based enterprisesystem to which it is connected, for later review and practice.

Therefore, the invention in one aspect consists of a method andapparatus for analysis and improvement of a selected athletic motion ofan individual, consisting the steps of using a computer-based motionanalysis system that has a processing computer, inertial sensors, avideo camera which may be of any analog or digital technology, and acomputer-driven display screen; testing an individual doing the athleticmotion, with a tool if a tool is implied, by monitoring the execution ofthe motion with multiple inertial sensors mounted on the individual andoptionally on the tool, with the video camera or cameras directed at theindividual in action. The athletic motion might be golf, baseball,hammering, sawing, throwing or using other handheld tools or sportsequipment, a small sampling of which may include balls, bats, rackets,clubs, paddles, oars, spears, hammers, screwdrivers, staple guns, darts,horseshoes, and axes and others. It extends to running, kicking,jumping, pedaling and other foot/leg athletic motions using footactuated tools and sports equipment including bicycles, balls, andfoot-operated levers and other tools and objects.

The video camera, when used, is carefully positioned in advance toinsure precise alignment with the individual under test and usefulpoints of reference for measurement and analysis of the motion. Thesensors are carefully positioned with the use of body wearableappliances to insure that sensor data will reflect body motionaccurately. Sensor data is collected from the sensors and video signalfrom the camera during the execution of the athletic motion; and thesensor data is analyzed by processing the sensor data into motion datarepresenting pre-defined selected performance parameters of pre-definedselected components of the athletic motion as may be accomplished by orattributable to specific or distinctive body segments such as the leg,hip, shoulder, neck, head, arm and hand aspects of a motion. The resultsof the analyzing is reported or presented in a form that includes a realtime, computer generated display of multiple, selectable configurations,one of which includes in a composite, synchronized combination of thevideo signal as a video display, a multi-color, three dimensionalanimation representing the motion of at least one color-coded bodysegment created from the motion data, and a time-based graph of multipleselected performance parameters.

There may be provision for setting a range of motion limit for selectedcomponents of motion such as a specific bending or flexing component ofthe motion in advance of the testing. The animation of the motion mayincorporate a three dimensional wire mesh cage or open framerepresenting the motion limits within which the body segment is visible.The software may provide for altering a selected color within thedisplay upon the occurrence of a motion exceeding the motion limits, asa highly visible, instant signal to the individual that the limit hasbeen reached or exceeded. Stepped levels of indication of approaching orexceeding pre-set limits may be used by using multiple color changessuch as from green to orange to red.

The analysis may include for selected parameters comparing the motiondata test value to a pre-defined benchmark value for the same parameterand determining a degree of deviation, and presenting on a time-basedgraph the test value and the benchmark value concurrently. The analysismay include calculating from the test values and the benchmark values ascore for each selected parameter. It may further include combining thescores of the selected parameters by a pre-defined formula so as toyield a single score representing the total performance value of theathletic motion as a kinetic index.

The system and software may include with or follow the report orpresentation with a prescription of a regime of training exercisesselected from a pre-defined list of exercises based on the amount of thedeviation from the benchmark values of individual parameters, and theexercises may be associated with a pre-defined list of training tools.The frequency and length of periods of exercise may be limited by theavailable training time of the individual, as may have been entered intothe processing computer ahead of the testing.

The wireless inertial sensors may employ a stacked topology within asensor enclosure wherein a battery is proximate to and its shapeconforms to the bottom of the enclosure, and sensor elements andelectronic circuitry are positioned over the battery within theenclosure. The sensors may be attached to body appliances that are wornby the individual. The sensors and the appliances may havecorrespondingly keyed mating structural by which the sensors areuniformly and repeatably attachable to the same place with the sameorientation on the appliances.

The results of the analyzing, including the motion data and the videodata, may be stored in a local or remote computer database and madeavailable for later replay locally or via a remote computer or computernetwork connected or connectible to the processing computer.

The camera may be set up in advance of testing using a reference targetor frame placed on the test site so as to define at least one point orline of reference relative to the motion to be tested. The software maybe configured for overlaying the video display during a calibrationphase with reference points, lines or other symbols relating to aspectsof the motion, such as alignment lines, center lines, balance points ofthe starting, ending or in-motion positions of the testee, by whichmotion can be more critically observed. The effectiveness of the linesand symbols overlaid on the video display may be dependent on correctcamera placement prior to testing.

Other and various aspects, goals and objectives of the invention will beapparent from the examples and illustrations that follow. Pronounsshould be interpreted in all cases to include both genders.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIG. 1 is a simplified flow chart depicting the basic, repetitive,step-level methodology of the invention in which improvements insequential performance testing are considered in the prescribing of thenext sequential set of exercises.

FIG. 2 is a diagrammatic illustration of the principle components of anembodiment of the invention, including the inertial sensor/transceiver,audio/video sensors, base transceiver, and computer with itscontrol/display unit, and internet connection to a enterprise host anddatabase.

FIG. 3A is a diagrammatic backside elevation view of a vest appliance ofthe invention, illustrating the location of a sensor pocket high on theback panel.

FIG. 3B is a diagrammatic perspective view of a waist belt appliance ofthe invention, illustrating the location of a sensor pocket on the backpanel.

FIG. 3C is a diagrammatic perspective view of a vest appliance and awaist belt appliance configured with sensors in sensor pockets hardwired to a control module on the waist belt appliance, from whichwireless transmissions of sensor data emanate.

FIG. 4A is a top view of one sensor embodiment, mounted on a gloveappliance.

FIG. 4B is a bottom edge view of the sensor of FIG. 4A, illustrating theattachment loops protruding from the curved underside of the sensorcase, by which the sensor is attached to the glove appliance.

FIG. 4C is a side edge view of the sensor and glove appliance of FIG.4A.

FIG. 4D is an exploded perspective view of the sensor of FIG. 4A,illustrating the stacked arrangement of electronic components over thecurved battery, and the attachment loops protruding from the underside.

FIG. 5 is an exploded perspective view of another sensor embodiment,that may be wired to a control module-transmitter for transmission ofsensor data.

FIG. 6 is a front face view of a control module to which body sensorsmay be wired for wireless transmission to a receiver/computer systemand/or local display of selected parameters of motion.

FIG. 7A is a front perspective view of a golf club sensor assembly,attached to the shaft of a gulf club.

FIG. 7B is a backside perspective view of the golf club sensor assemblyof FIG. 4 g.

FIG. 7C is a cross section view of the golf club sensor of FIG. 4 g.

FIG. 8 is an illustration of one embodiment of the system and method ofthe invention in use, consisting of a golfer wearing vest and waist beltappliances mounted with inertial sensors and holding a golf club with aninertial sensor mounted just below the grip of the club, standingadjacent to a stand supporting a video camera directed at the golfer andan associated receiver and processing computer with keyboard anddisplay, the display being viewed by an instructor.

FIG. 9 is a screen shot of the composite display of the invention,incorporating three formats of feedback: a live video feed of the golferin the upper left portion of the display, an animation of the golfer inthe upper right portion of the display that is color coded todistinguish major body segments; and in the lower portion of the displaya motion data time line graph tracing hip, shoulder and hand motions ina multi-colored trace.

FIG. 10A is a screen shot of a composite display of the invention,incorporating three formats of feedback: a live video feed of the golferin the lower left side portion of the display; a time-stepped animationof the club swing indicating the plane of the club swing and the handorientation during a swing motion; and three motion data time linegraphs showing the club speed in three axis.

FIG. 10B is a line graph indicating posture with respect to trunk flexextension and trunk lateral bending versus time during a swing motion.

FIG. 10C is a line graph indicating degree of pivot during a swingmotion.

FIG. 10D is a line graph indicating degrees of hip segment rotation,shoulder segment rotation, and torso load during a swing motion.

FIG. 10E is a line graph indicating degrees of shoulder segmentrotation, arm segment rotation, and upper body load during a swingmotion.

FIG. 10F is a line graph indicating alignment of hip segment rotation,shoulder segment rotation, arm segment rotation versus time during aswing motion.

FIG. 10G is a line graph indicating hip segment rotation speed, shouldersegment rotation speed, and arm segment rotation speed during a swingmotion.

FIG. 11 is a screen shot of the multi-color animation illustrating thecolor distinction between the shoulder segment and the hips segment ofthe animation.

FIG. 12 is a screen shot of a multi-color animation illustrating thecage by which user settable parameters for lateral bending during swingmotion are made apparent to the golfer as real-time feedback.

FIG. 13 is a screen shot of a multi-color animation illustrating thecage by which user-settable parameters for flexing during the swingmotion are made apparent to the golfer as real-time feedback.

FIG. 14 is a screen shot of a multi-color animation illustrating thecage by which user-settable parameters for rotation during the swingmotion are made apparent to the golfer as real-time feedback.

FIG. 15 is a screen shot of a multi-color line graph illustrating thecoordination in time and amplitude of the rotational velocities of thehips, shoulders, and hand of the golfer during the swing motion.

FIG. 16 is a simplified representation of a multi-step process for thereduction of multiple primary performance parameters to a fewer numberof secondary performance parameters, hence to respective body and clubperformance factors, and finally to a single kinetic index reflecting anobjective evaluation of the total performance of a swing motion.

DETAILED DESCRIPTIONS

An athletic motion analysis system and method for improving performanceaccording to various aspects of the present invention consists ofequipment and methods, including cameras, inertial sensors, computers,computer networks, and software, means for providing real time visualfeedback in unique formats and prescriptions for practice exercises, allas described in the following paragraphs. The invention comprises manyembodiments and variations of which the following examples areillustrative and not limiting.

Referring to FIG. 1, the steps of one embodiment of the invention arepresented in sequence. Test 100 requires that the user subject him orherself to testing by use of the system of the invention while he/sheconducts an athletic motion of interest. Collect 200 includes themeasurement and collection of motion data with inertial sensors, acamera, and possibly other sensors, of the motion executed during thetest. Analyze 300 includes analyzing the collected data, and includesaccessing a database 700 of related data for comparison and for relatingtypes and degrees of deviations in performance from benchmark values toa library of standard exercises for generating prescriptions ofappropriate practice exercises or corrective measures. Report 400includes the generation of a unique display of synchronized video,motion animation and data/time graphs. Prescribe 500 includes thedocumentation and delivery of a program or regime of type and time orquantity of performance parameter-specific exercises. Finally, exercise600, instructs the user to practice the exercises or corrective measuresin accordance with the prescription. The cycle of test, collection,analysis, report, prescription and exercise is repeated as often asdesired until the desired level of performance is achieved. The type,time and level of the prescribed exercises are adjusted automatically(up or down) according to the most recent performance and/or the changein performance between the most recent performance test and priorreported test results.

Referring to FIG. 2, the principle components of one embodiment of thesystem and their relationship is represented in a system diagram whereinertial sensors 10, attached to body appliances 40 that are worn by theuser, communicate by wireless means with a base transceiver 69 which ispart of a computer-based motion analysis system 70 that includes acontrol and display capability, such as a laptop computer, with suitableapplication software and an onboard or connected database 700. Othersensory devices 72, at least one video camera and optionally amicrophone and other sensors, are connected to system 70 by wire orwireless means. System 70 processes motion data and generates, displaysand/or transmits reports and prescriptions as described in more detailbelow. Training tools 60 are not directly linked to motion analysissystem 70 or the other associated components, but may be used by theuser or testee during practice exercises as prescribed by the systemafter testing and analysis, all as is further explained below.

System 70 and its related components may be operated at times on astand-alone basis, but may always or at times be connected orconnectable to a remote, knowledge-based enterprise system and database98 via a browser-based internet access point or other high speed dataconnection for conducting data transfer and enterprise relatedactivities between the host and local systems.

For example, a website for the enterprise system and host database 98may provide access for registered user systems 70 to the host company'sinformation, motion analysis products and services information,management information, company news, user access via a log-in screenfor product and service FAQs, news letters, and database 700 librariesof past performance and benchmark data and exercises, and updatesthereof.

The website may be configured to provide such global functionalities toregistered users as general prescriptions and exercise instructions,explanations, and illustrations—text and/or audio/video, clubhouseevents and news, discussion forums, special links for members, globalFAQs, an on-line store link, special newsletters, and access to relevantdocuments and training tips. The website may be divided by categories ofregistered users pages as between student users and instructor users andprovide such particular functionalities as either group might need, suchas for instructors the history of instruction sessions by studentportfolio, the history of student analysis by portfolio, with sessionsorganized or stored in respective student “locker rooms” by portfolio,and scheduling for student sessions. Student pages may provide suchfunctionalities as the individual's own personal data, history of hissessions and analysis, his training calendar, instructor contact info,and his golf scores and stats logbook.

There may be a third class of user, an organization user such as a golfschool or academy, where a subset of the enterprise system is treated asan OEM client or model, with its own branding, hosting multiple studentsand instructors as described above.

Individual systems of the invention work in stand-alone configurationsas individual test and evaluation systems for collecting studentperformance data, analyzing and comparing student data to a library ofperformance data including expert performance data, reporting theresults, and prescribing corrective exercises. New test results areadded to the database, and may be delivered to or accessed by coachesand/or students via on-line access to internet services. Individualsystems may share access to a host database of test results of otherusers and related practice drills for study or comparative purposes.

Alternate embodiments of the invention may be directed to otherathletic, occupational, or rehabilitation motion analysis and trainingof animals or humans, at either an enterprise level or a local systemlevel as described below.

Referring to FIGS. 3A, 3B, 3C, 4A, and 4C, various embodiments of bodyappliances for attaching motion sensors to the user's body and/or golfclub are illustrated. The appliances are designed to be repeatablydonned by the user such that the sensor assemblies are positioned andrepeatedly repositioned in the same place on the body or club foroptimal motion sensing at selected critical points of anatomy,particularly skeletal anatomy and/or tool structure, where they willprovide motion data sufficient to define the initial position and fullrange of motion such that it can be reduced by data processing to themajor component motions. The appliances are further refined structurallyto minimize or avoid interference with body motion during execution ofthe movement under study. The appliances are yet further refined toretain body or tool position and to retain the relationship of thesensor assembly to the target area of the body or tool during normalbody motion, including any strenuous flexing and/or accelerationassociated with the motion under study, so that the change of positiondata reported by each sensor most accurately reflects the real timeexperience of the target area of the body and/or tool.

In one example, for a golf swing analysis system, there are a series ofthree appliances for mounting inertial sensors to the user's body. Thereis a vest appliance 40 (FIG. 3A) suitable for mounting an inertialsensor, referred to as a shoulder sensor, high on the user's back aboveand between the shoulder blades over the spinal column; a waist beltappliance 50 (FIG. 3B) for mounting an inertial sensor, referred to as ahip sensor, low on the user's back just above the hips and over thespinal column; and a glove appliance 58 (FIGS. 4A and 4C) for mountingan inertial sensor to the back side of the user's forehand.

Referring to FIGS. 3A and 3C, vest appliances 40 and 40A respectivelyhave a back panel 41 at the top of which is attached a sensor pocket 42suitable for snuggly securing a respective sensor 10 or 10A. Not visiblein the figures but easily understood, the back side of the pocket thatwill receive the underside of the sensors of FIGS. 4B, 4D, and 5, isslotted to accept mounting loops 12 in a keying manner that enhances thegrip and position integrity of the sensor within the pocket of theappliance.

The slots or sockets for receiving the sensor loops may be characterizedas mounting structure, and may be further configured with latchmechanisms that secure the sensor loops 12 within the receiving slots orsockets of the sensor pocket with a mechanical interlock. Variations ofthe sensor loop structure as a mounting clip or stud and of the pocketslot as a keyed receiver structure, with a latching mechanism such astwist or click fit mechanism incorporated on either or both theappliance and the sensor are within the scope of the invention. Thesensor pocket may be reduced in this instance to a mere location on theappliance rather than a full or partial enclosure for the sensor.

Shoulder straps 43 extending from the top corners of back panel 41attach to strap ends 43A extending from the lower corners of the backpanel via buckles. Chest belt sections 44 and 44 a extend from the lowercorners of the back panel for buckling on the front side of the wearerat about the level of the bottom of the rib cage or kidneys. All strapsare adjustable in length for proper fitment to the wearer. The elongatedback panel provides stability to the sensor from rotationaldisplacement. The relatively high waist level of the chest strapprovides security from vertical displacement of the sensor, and avoidsinterference with the waist belt appliance 50.

Referring to FIGS. 3B and 3C, waist belt appliances 50 and 50Arespectively, have a belt panel 51, the center section 52 of which isfabricated of non-stretch material, and is configured with a sensorpocket 53, with mounting loop slots as described above, sized andsuitable for snuggly securing either a sensor 10 or 10A. Belt straps 54and 55 extend from left and right ends of belt panel 51 and are buckledtogether at the front of the wearer.

Referring to FIGS. 4A, 4B, and 4C, glove appliance 58 is configured witha backside strap 59, the end of which is threaded through loops 12(FIGS. 4D and 5) of sensor 10 and secured by hook and loop material orother commonly known fastener means to glove appliance 58. As with theother appliances, the loop and strap means of attachment may in thealternative be a hard mechanical interface between a suitable structureincorporated into the back of the glove appliance and a mating structureon the sensor.

Referring to FIGS. 4A, 4B, 4C, and 4D, and sensor 10 in particular, thepackaging of the battery, sensor, transmitter, and the internalcircuitry for data processing, transmission, and for recharging thebattery, is uniquely designed to: (1) minimize the package size andweight; (2) place the center of mass as close as possible to the contactsurface side of the sensor to minimize inertial forces tending to rotateor displace the sensor within its appliance relative to the intendedtarget area of the user's body; and (3) to optimize the location of thesensing elements within the package to be as close to the center of thesensor's footprint as practical for best intuitive alignment of thesensor over the target area. To this end, the sensor uses a stackedconfiguration which places the relatively thin battery (the heaviestcomponent and majority mass of the sensor) at the bottom closest to andconforming to the curved shape of the underside or user contact surface,with the circuit boards and sensing elements above it, only slightlyfurther outboard from the user.

Each sensor has a unique identifier that is encoded within the outputdata stream, for unambiguous identity during multi-sensor operation.While not strictly necessary, in typical systems sensors are mounted intheir appliances on the body with a consistent, pre-determinedorientation or “up” end direction, simplifying the calibration and dataprocessing.

Referring to FIG. 4D, one embodiment of a wireless inertial sensor 10 ofthe invention consists of an enclosure having a bottom cover 14 and atop cover 28, within which is housed a lithium battery 16, electronicsshelf 18, printed circuit board 20 with switch, battery chargercircuitry, on/off button 22, sensor assembly 24 which includes thetransmitter, and light pipe 26. The lithium battery 16 conforms to thecurved shape of bottom cover 14. It is readily apparent that the mass ofbattery 16, a substantial portion of the sensor mass, is distributedacross and close to bottom cover 14. This stacking arrangement with thebattery at the bottom provides a very low center of gravity for thesensor, improving its resistance to rotational or sliding displacementwithin the pocket of the appliance or on the back of the hand duringbody motion. The flat, relatively thin battery shape permits theinertial sensor to be outboard of the battery and the sensor package toremain relatively thin.

As described above, referring to FIGS. 4B, 4D and 5, mounting loops 12extend from bottom cover 14 and provide for mounting stability in tworespects. Sensor pockets 43 and 53 (FIGS. 3A, 3B, and 3C) in vest andwaist belt appliances are configured with slots (not shown but readilyunderstood from this description) that receive mounting loops 12,providing a keying effect for proper insertion and positioning of thesensors within the pockets.

Referring to FIG. 5, this embodiment sensor is a wired inertial sensor10A and consists of an enclosure having components analogous to those ofsensor 10 (FIG. 4D), but the enclosure shape and configuration ofcomponents is adapted to use a conventional 9 volt battery positioned atone edge of the enclosure, accessible through battery door 15, ratherthan the stacked order of assembly of sensor 10.

Referring to FIGS. 3C and 6, there is in one embodiment of the motionanalysis system a control module 30 wired to sensors in sensor pocket 42and 52 via cables 38 and 36 for receiving motion data. It has a hingedattachment 32 to belt 54 so that controls 31 and display 33 are easilyviewable by the user. There is internal data processing capability anddisplay driver for providing information directly to the user, and anintegral wireless transmitter or transceiver for transmitting data to amotion analysis system 70 (FIG. 2), and/or receiving setup or other dataor instructions from the motion analysis system.

Control module 30 is configured with a battery pack, hip sensor input,shoulder sensor input, micro computer, keypad, LCD display, USBconnection, remote sensor and system transceiver capability, andoptionally with a video game interface.

Referring to FIGS. 7A, 7B and 7C, there may in addition or in thealternative to the body worn appliances, a mounting appliance attachableto the tool or in this case golf club, for mounting a sensor.Alternatively, the mounting means may be incorporated into the sensorenclosure as in wireless club sensor 11, where the back cover 13incorporates a latch mechanism 15 for securing sensor 11 to the shaft 21of a golf club. Top cover 17 encloses the battery at its lower end,accessible via battery door 19, while the electronic circuitry andsensor elements are contained in the upper section closer to the grip ofthe club.

Referring now to FIG. 8, there is illustrated of one embodiment of thesystem and method of the invention in use, consisting of a golferwearing vest appliance 40 and waist belt appliance 50 which are eachequipped with a wireless inertial sensor as described above. The golferis holding a golf club with an inertial sensor 11 mounted just below thegrip of the club, standing adjacent to a stand 71 supporting a videocamera 72 directed at the golfer and an associated receiver andprocessing computer system 70 with keyboard and display, the displaybeing viewed by an instructor.

The camera positions and direction with respect to the golfer'sposition, size and posture are carefully aligned with respect to thetest site from one or the other or both of at least two positions: afirst camera position at a specific down line angle, height, and lateralposition or offset, and another camera position for face on angle,including height and offset. Correct camera positioning enablesplacement of an overlay in the video display that includes vertical andhorizontal alignment lines representing center of alignment and centerof balance. There may be multiple cameras on additional stands orientedto capture the motion from different directions and different heightsand offsets, and some or all may be positioned carefully to support thefurther use of overlays of alignment lines relating to the golfer'sposition, size, posture, and expected motions, so as to make motions anddeviations in alignment very apparent in subsequent video presentationsof the swing motion.

Stated more generally, prior to testing, it may be required to selectand define a test site to have at least one motion reference point; tothen position the video camera to be directed at the test site at apre-defined angle of rotation around the point or test site, a specificheight relative to the reference point, with a specific angle ofelevation and lateral offset with respect to the reference point.Thereafter a video test signal of the test site and reference point issent to the computer-driven display screen and an overlay is insertedonto the computer-driven display screen corresponding to the referencepoint, from which specific motions are more easily observed.

The processing computer or PC of system 70 performs relationalcalculations on the parameters received from the various sensors,thereby allowing computation of various golf-related parameters ofinterest. As an example, the PC can calculate club-face angle or theangle through which the golfer turns his or her shoulders while swingingthe golf club. Such parameters are referred to here as performance oralternatively diagnostic parameters, to distinguish them from the rateor position parameters transmitted by the sensors to the PC.

In a golf swing motion analysis system in particular, rate and positionmotion data are typically processed by the application software intoperformance or diagnostic parameters relating to the golfer's bodysegment performance, including: hip velocity (degrees per second); hiprotation (degrees negative and positive); shoulder velocity (degrees persecond); shoulder rotation (degrees negative and positive); club release(degrees per second); club speed (miles per hour); club face rotation(degrees open/closed); club path (degrees inside or outside of club'saddress position); hip linear movement (centimeters left or right ofneutral address); hip and shoulder separation (time difference betweenmaximum hip, shoulder, and club velocity); flexion/extension of hipsegment (centimeters traveled along z-axis); and kinetic link. Theseparameters are further extrapolated to yield a predicted resulting “ballin flight” performance of parameters: spin (degrees per second); launchangle (degrees); carry distance; roll distance (yards); total distance(yards); distance traveled off line (yards right or left); ball flightcharacter (fade, draw, hook, slice, push, pull, straight); and PTI orpower transfer index.

This processed information is reported to the golfer in a unique,synchronized, multi-format presentation of the swing motion that isavailable in real time and/or playback mode for optimal user andinstructor assimilation.

FIG. 9 is a screen shot of the synchronized, composite display of theinvention, incorporating three formats or forms of feedback. In a realtime feedback or “biofeedback” mode, there is a live video feed of thegolfer, typically a face on or side view, presented in the upper leftportion of the display although it may be placed elsewhere in thedisplay, in which the alignment lines are applied during a set up phase,are stationary and the motion with respect to the alignment lines isreadily apparent.

A multi-color animation of the golfer, generated from the inertialsensor motion data, is presented in the upper right portion of thedisplay, although it may be positioned elsewhere in the display. Theanimation may be color coded to distinguish major body segments, e.g.the shoulders segment versus the hips segment. The animation may beoriented to view the swing motion from any useful angle, depending onwhat aspect or component of the swing motion is being scrutinized at thetime.

In the lower portion of the display a motion data time line graph traceship, shoulder and hand motions in a multi-colored trace, although it maybe positioned elsewhere in the display. The graph may present simply thecomponent motion data from the instant swing motion, and demonstrategraphically the coordination between hips, shoulders and hand motion; orit may present a comparative trace of the present motion or component ofmotion compared to a prior motion or an expert motion in order toillustrate the degree of deviation and required improvement to achieve adesired performance level.

Referring to FIG. 10A, another example of the composite, multi-format,synchronized display is a screen shot of a composite display of theinvention, incorporating the three formats of feedback of FIG. 9: avideo record of the golfer this time in the lower left side portion ofthe display; a stepped frame animation of the club swing indicating theplane of the club swing and the hand orientation during a swing motion;and three motion data time line graphs showing the club speed in threeaxis.

The stepped frame animation is a useful device for illustrating theplane, path or arc of a motion or component of motion, and is a furtherenhancement of the presentation. Selected positions of a point or objector portion of the video screen are retained as the video progresses soas to show the path leading up to the present position. The steppedaspect of the presentation can be done as function of time, or of linearor angular displacement of the object or point of interest, whicheverbetter serves to illustrate the path of motion best for the viewer.

Stated more generally, the multi-color, three dimensional animationrepresenting the motion of at least one color-coded body segment createdfrom motion data may include or be in some embodiments a stepped frameanimation where selected positions of an object in motion are retainedin subsequent frames of the animation such that a motion track of theobject is apparent to a viewer. The retained positions may be programmedto be selected on the basis of time, position, speed, or acceleration ofthe object in motion.

The orientation on the screen of these multiple forms of simultaneouspresentation may be varied. There may be additional information as well,space permitting. A composite presentation of video, animation, andmotion data graphs enhances the user's ability to quickly assimilate andappreciate the subtle differences at the component level of the swingmotion, between his current performance and the desired performance. Amulti-dimensional presentation of the swing performance can be watchedin real time, in an instant replay mode, or in a later review.

The system 70 also offers alternative and supplemental forms ofpresentation or “report” of the swing performance. Expanded graphs, forexample, help clarify the timing of components of motion, as well as theamplitude. For example FIG. 10B is a line graph indicating posture withrespect to trunk flex extension and trunk lateral bending versus timeduring a swing motion. FIG. 10C is a line graph indicating degree ofpivot during a swing motion. FIG. 10D is a line graph indicating degreesof hip segment rotation, shoulder segment rotation, and torso loadduring a swing motion. FIG. 10E is a line graph indicating degrees ofshoulder segment rotation, arm segment rotation, and upper body loadduring a swing motion. FIG. 10F is a line graph indicating alignment orcoordination of hip segment rotation, shoulder segment rotation, armsegment rotation motions versus time during a swing motion. FIG. 10G isa line graph indicating hip segment rotation speed, shoulder segmentrotation speed, and arm segment rotation speed during a swing motion.

The animation capability of the system, driven by the inertial sensorinputs, offers additional opportunities for presenting more detailedillustrations of the swing motion in real time or playback mode. Forexample, FIG. 11 is a screen shot of a multi-color animationillustrating the color distinction between the shoulder segment and thehips segment of the animation. This makes for easy and quick distinctionbetween these components of the full swing motion. The numerical valueof peak or range of rotation, flexion, and side bend are posted left andright of the animation for calibrating the user's perspective of theanimation motion.

The animation capability provides yet a further training tool in theform of animated “cages” or scalable limits of selected parameters thatcage the animated figure and illustrate the golfer's movement within thethree dimensional frame. FIG. 12 is a screen shot of a multi-coloranimation illustrating the box or cage by which user settable parametersfor lateral bending during swing motion are made apparent to the golferfor real time feedback. The processing computer 70 can create aninstantly apparent change to the display, for example by turning thebackground orange for close calls and red for actual violation of thecage parameters during a swing motion.

Further examples of the power of motion data animation as part or all ofthe presentation or “report” part of the methodology follow. FIG. 13 isa screen shot of a multi-color animation illustrating the threedimensional grid or open frame by which user-settable parameters forflexing during the swing motion are made apparent to the golfer asreal-time feedback. FIG. 14 is a screen shot of a multi-color animationillustrating the “box” by which user-settable parameters for rotation.

The animation capability of the system can also be used to present anenhanced version of the time line traces or graphs. FIG. 15 is a screenshot of a multi-color line graph illustrating the coordination in timeand amplitude of the rotational velocities of the hips, shoulders, andhand of the golfer during the swing motion.

It should be noted that although FIG. 11 through 15 are illustrated hereas full screen shots; these and other animations of the motion data andsettable parameters are within the scope of the invention and can bepresented in the multi-format form of FIG. 9, with synchronized videoand graphs.

It is a goal of the invention to provide an objective, consistentanalysis of each performance. The methodology of the invention dependson capturing motion data, processing it into the described parametersrelating to body segments and components of the motion, providing aquantitative analysis of each component of motion, and then summing thescores for each component of motion so as to produce a unitary number or“kinetic index” for the performance as a whole. One embodiment of asystem 70 for golf swing motion analysis processes motion data againstbenchmark values to produce a value on a uniform index scale of 0-50 foreach of the following primary performance parameters: sequence, speed,stability, mobility, transfer, timing, club performance, and clubaccuracy. These values are summed in a pre-determined order to arrive ata unitary number representing the kinetic index for the totalperformance on a scale of 0-100, as described further below.

Objectivity and repeatability of the system for motion analysis dependson a consistent process that examines and gives weighted considerationof all relevant aspects of the motion in calculating a final performancefactor or kinetic index. Referring now to FIG. 16, one aspect of themethodology of this embodiment is illustrated in an objective,repeatable, computer-automated reduction of the basic or primaryperformance parameters 1-8 measured by system 70 against pre-selectedbenchmark values, into a single kinetic index. The system uses amulti-step process that sums the primary parameters into secondaryparameters 9-12, then into body performance factor 13 and clubperformance factor 14, and finally merges these values into kineticindex 15, a quantification of the overall performance value of the swingmotion being analyzed.

The FIG. 16 performance parameters are explained below:

Primary Parameters:

-   -   1. Sequence: This parameter relates to the degree of timing and        coordination of the rotational velocities of hips, shoulders and        arms during the swing motion. For example, at 120 frames per        second, the target or benchmark standard sequence for a golf        swing motion is assumed to have maximum hip rotation velocity        occur at 36 frames before maximum shoulder rotation; which        should occur at 24 frames ahead of maximum arm rotation; which        should occur at 16 frames ahead of the club impact on the ball.        The total deviation in frame count from the pre-established or        assumed ideal sequence for all segments is inversely weighted        against a total maximum score or ideal performance index for the        sequence parameter of 50, yielding a relatively lower score for        respectively larger deviations.    -   2. Speed: This parameter relates to the maximum peak rotational        velocity of each body segment. The benchmark is set at: 400        degrees/second for hip rotation; 800 degrees/second for        shoulders rotation; 1600 degrees/second for arms rotation; and        3200 degrees/second for club rotation. The sum of the        differences is weighted inversely against a maximum score of 50,        yielding a relatively lower score for respectively larger        differences.    -   3. Stability: This parameter relates to the orientation of the        hip segment and shoulder segment in relation to the spine. It is        measured in degrees. The benchmark for hips, shoulders, and arms        are all 0 (zero). Again, the sum of the differences is weighted        inversely and scaled against a maximum index of 50.    -   4. Mobility: This parameter relates to the relative range of        angular rotation of hips, shoulders, arms around the spine. The        benchmark is that they be equal. The sum of the differences are        weighted inversely and scaled against a maximum index of 50.    -   5. Transfer: This parameter relates to the sum of the ratio of        angular momentum of the hips to the shoulders, and hence to the        arms. The measured transfer ratio is scaled against a benchmark        maximum ratio of 6 and equated to a maximum index of 50. For        example, using benchmark values, if 400 degrees/second of hip        rotation produces 800 degrees/second for shoulders rotation,        that is a transfer ratio of 800/400=2.0. Then if 800        degrees/second shoulders rotation results in 1600 degrees/second        for arms rotation, and 3200 degrees/second for club rotation,        then those transfer ratios are also 2.0 and 2.0 respectively;        the sum of which is 6.0. A lesser actual score is divided by 6        and multiplied by 50 to generate a base-50 index score.    -   6. Timing: This parameter relates to the difference in time or        coordination of maximum rotational velocities of hips,        shoulders, and arms in time. The scoring is based on the delta        or difference in timing in the manner described above, scaled        against a maximum index of 50.    -   7. Club Performance: This parameter relates to the linear        acceleration of the club, added to peak angular release        velocity. The benchmark is 300 mph (miles per hour) for linear        acceleration and 400 degrees/second of angular velocity. The        simple sum, 700, is equated to a maximum performance index of        50, and the measured value scored accordingly.    -   8. Club Accuracy: This parameter relates to the three        dimensional movement of the club on the ball and is graded on        the velocity of the straight-on axis less the velocities in each        of the orthogonal axis, in miles per hour. The total is compared        to a benchmark and the result scaled to a maximum performance        index of 50.        Second Order Parameters

The primary parameter scores 1-8 are reduced in a first step by a simplesumming of related parameters as follows:

-   -   9. Sequence & Speed: the sum of the individual indexes of        sequence 1 and speed 2 above, having a maximum index of 100.    -   10. Stability & Mobility: the sum of parameters 3 and 4 as        above.    -   11. Transfer & Timing: the sum of parameters 5 and 6 as above.    -   12. Club Power Accuracy: the sum of club performance 7 and club        accuracy 8 indexes.

These second order parameters are further reduced to a body performancefactor 13 and a club performance factor 14 as follows:

-   -   13. Body Performance Factor: the sum of parameters 9, 10, and 11        divided by 3, having a maximum index of 100.    -   14. Club Performance Factor: simply the club power accuracy 12        index brought forward.

The body and performance factors 13 and 14 are summed and divided by 2to yield the:

-   -   15. Kinetic Efficiency Index: having a scale of 0 to maximum        100.

It will be appreciated that the pre-selected benchmark values of theindividual parameters are somewhat arbitrary, selected to provide aperformance challenge to the anticipated range of skills of a targetpool of testees. The use of other or alternative benchmark values andscoring formulas is within the scope of the invention. Also, theselection and ratio or weight giving to each performance parameter inthe reduction process is somewhat arbitrary, the requirement being thateach parameter is given a weight or degree of consideration recognizedto be relevant to the overall performance.

The reduction process of primary performance parameters into a finalkinetic index in the context of a golf swing analysis reflects thekinetic chain philosophy, that the performance value of the total motionis the sum of the performance value of the component parts of the motionexecuted in an optimal sequence, in order to transfer maximum energy andaccuracy from feet to hips to shoulders to arms to the club andultimately to the ball.

While this description of motion analysis and performance measurementhas been cast in the context of a golf swing; the apparatus andmethodology is equally applicable to other athletic motions involving,for example, running and kicking leg motions and swinging or choppinghand and arm motions.

Having evaluated individual performance parameters, which may also bereferred to as “diagnostic” parameters, the system is able to comparethe performance results to a catalog of exercises appropriate to therespective parameters and their test result, and provide an automatedrecommendation or prescription of exercises. The system may be furtherpreprogrammed with the testee's available training schedule and henceable to tailor the prescription to the training time available, withemphasis on the parameters most in need of improvement. In other words,referring back to FIG. 1, the invention extends the automated,objective, Report on performance to include a Prescription forimprovement.

In this regard, performance parameters are also characterized asdiagnostic parameters. In the golf swing context, they may relate tosubsets, body segments or components of the motion including: feet, hip;and shoulder performance. For example, diagnostic parameters of CBL(center balance line) extension and flexion, and of CAL (centeralignment line) left and right lateral bending, relate to feetperformance. Exercises appropriate to CBL extension problems are scaledaccording to a pre-determined scheme to the severity or priority of theproblem, on a scale of 0 (acceptable performance) to −20 degrees(significantly below acceptable performance). A rating of −5 degrees maygenerate a prescribed exercise called “posture stick”, using particulartraining tools; a relatively lower rating of −10 may call for the sameexercise but with a different training tool; and so on. The “posturestick” exercise, for example, requires manipulation of a club in aprescribed manner while standing on a base platform, to acquire andpractice attaining a stance with the correct alignment of the majorjoint centers of the body for creating an optimal muscle length tensionrelationship to enhance the body's postural equilibrium. Other exercisesare similarly focused on particular body segments and components of thegolf swing.

The initial selection of exercises and tools and the pre-determinedscheme for allocation of particular exercises for improving particularperformance parameters is somewhat arbitrary, but calculated to induceimprovements in performance of components of motion and hence to thetotal motion performance if practiced as prescribed. The following table1 lists one embodiment of diagnostic parameters and appropriateexercises by priority by which prescriptions would be issued by thesystem to a user.

TABLE 1 Diagnostic Parameters and Exercises Relating to Components ofMotion Test/ Measurement Deviation Subject Area Parameter (degrees)Prescribed Exercise/Tool Feet Center Balance 0 No Drill Posture LineExtension #1 −5 Posture Stick/K-Pillow & club −10 Posture Stick/FullFoam Roller & club −15 Posture Stick/Half Foam Roller & club −20 PostureStick/Base Platform & club Center Balance 0 No Drill Line Flexion 5Posture Stick/K-Pillow & club 10 Posture Stick/Full Foam Roller & club15 Posture Stick/Half Foam Roller & club 20 Posture Stick/Base Platform& club Feet Center Align. 0 No Drill Posture Line, Left #2 Lat. Bend. −2Mini Drawbacks/Balance Board & club −5 Mini Swings/Balance Board & club−10 Mini Swings Level 2/ Balance Bd & club −15 Mini Swings Level 1/Balance Bd & club −20 Mini Swings/Base Platform & 5 Iron Center Align. 0No Drill Line, Rt. Lat. Bend. 2 Mini Drawbacks/Balance Board & club 5Mini Swings/Balance Board & club 10 Mini Swings Level 2/ Balance Bd &club 15 Mini Swings Level 1/ Balance Bd & club 20 Mini Swings/BasePlaform & 5 iron Hip Rotation, Left −20 No Drill −25 Hockey Swings/BasePlatform & club −30 Double Post Swing/Base Platform & club −35 MiniSwings/Full Foam Roller & club −40 Mini Swings/Half Foam Roller & clubRotation, Right 20 No Drill 25 Hockey Swings/Base Platform & club 30Double Post Swing/Base Platform & club 35 Mini Swings/Full Foam Roller &club 40 Mini Swings/Half Foam Roller & club Shoulders Rotation, Left(neg)0-10 No drill (neg)15-20 Torso Twist/Base Platform & Stability Ball(neg)25-30 Torso Twist Counter & Primary/Base Plat. (neg)35-40 TorsoTwist Blast/Base Platform (neg)45-50 Torso Twist Drawbacks/ BasePlatform Rotation, Right 0-10 deg No drill 15-20 deg Torso Twist/BasePlatform & Stability Ball 25-30 deg Torso Twist Counter & Primary/BasePlat. 35-40 deg Torso Twist Blast/Base Platform 45-50 deg Torso TwistDrawbacks/ Base Platform Hip Linear Address 0-2 cm Double PostSwings/club to Max Backswing 3-5 cm Bentley Swings/Base Platform & club6-8 cm Hans Jumps/Impact Bag & Base Platform Linear Impact 0-2 cm DoublePost Swings/club to Max Finish 3-5 cm Bentley Swings/Base Platform &club 6-8 cm Hans Jumps/Impact Bag & Base Platform Hips Static Posture 0No drill 1-10 deg Posture Stick/Base Platform & club Shoulders StaticPosture 0 No drill 1-10 deg Posture Stick/Base Platform & clubTable 1: Diagnostic Parameters and Exercises Relating to Components ofMotion

Explanations and detailed instructions for the user's prescribedexercises are available on the local system 70, or may be accesseddirectly or remotely via an internet access to a host enterprise (FIG.2) with which the local system 70 is affiliated.

Referring to FIG. 1, steps of Test 100—Prescribe 500 require at least alocal system 70, while the exercise step 600 is, of course, executed bythe testee until he or she is ready to retest. A change in performancein a given primary parameter may or may not change the final kineticindex, but it will result in a change in prescription to a next level ofexercise applicable to that performance parameter.

The description above is largely directed to exemplary embodiments ofthe invention. Specificity of language and statements of advantageousperformance in this specification do not imply any commensuratelimitation on the scope of the invention, nor do they require the statedperformance. Thus no one embodiment disclosed herein is essential to thepractice of another unless indicated as such. Indeed, the invention, assupported by the disclosure including specification, claims, abstract ofthe disclosure, and figures provided, includes all systems and methodsthat can be practiced from all suitable combinations of the variousaspects disclosed, and all suitable combinations of the exemplaryelements listed. Such combinations have particular advantages, includingadvantages not specifically recited herein.

Alterations and permutations of the proffered embodiments and methodswill become apparent to those skilled in the art upon review of thespecification, claims and drawings. Although the disclosed system isparticularly suitable for analysis and improvement of golf swings,variations can be implemented, for example, for analysis and improvementof other athletic motions such as racquet sport swings like tennis, orfor analysis of other motions, including animal motions, particularlyusing the biofeedback mode and motion analysis and prescriptiontechniques, such as to diagnose and recommend courses of treatment forphysical therapy. Accordingly, none of the disclosure of the embodimentsand methods constrains the scope of the invention. Rather, the claimsissuing hereon or on one or more applications claiming benefit of thisapplication or the applications to which it claims priority willvariously define the invention.

A system and method for analyzing and improving the performance of anathletic motion such as a golf swing may require: instrumenting a userwith inertial sensors and optionally with video cameras and monitoring agolf swing or other athletic motion of interest; drawing upon andcontributing to a vast library of performance data for analysis of thetest results; the analysis including scoring pre-defined parametersrelating to component parts of the motion and combining the parameterscores to yield a single, kinetic index score for the motion; providingan information rich, graphic display of the results in multiple formatsincluding video, color coded and stepped frame animations from motiondata, and synchronized data/time graphs; and based on the resultsprescribing a user-specific training regime with exercises selected froma library of standardized exercises using standardized tools andtraining aids.

Other and various examples and embodiments equivalent to and within thescope of the claims that follow will be apparent to those skilled in theart.

We claim:
 1. A method for analysis of a body motion of an animal orhuman subject, comprising: using a computer-based motion analysis systemcomprising multiple, body mountable, inertial sensors in communicationwith a processing computer connected to a computer-driven displayscreen; mounting the multiple inertial sensors to the body of an animalor human subject of interest at target areas of the body relating to abody motion of interest; calibrating the inertial sensors for initialalignment and orientation of each respective target area of the body;setting range of motion limits for selected body segments of said bodymotion; monitoring the execution of a said body motion with the motionanalysis system; collecting sensor data from said motion sensors;processing said sensor data so as to generate an animation and motiondata representing the body motion of said subject, said animationcomprising at least two color coded body segments wherein one bodysegment is color coded in a different color than the other body segment;displaying the animation of the body motion on the display screen;displaying on the display screen a visually apparent, rectangular, threedimensional open frame cage representing said motion limits for eachsaid selected body segment, within which said animation of said selectedbody segment is visible; and comparing the generated motion data toexisting motion data and calculating performance parameters related tothe body motion.
 2. The method of claim 1, comprising: prescribing aregime of training exercises selected from a pre-defined list ofexercises where each exercise is associated with at least one saidperformance parameter, and the order and amount of each exercise of theprescribed regime is associated with the relative levels of saidperformance parameters.
 3. The method of claim 1, said body motionrequiring manipulation of an associated object, said subject comprisingthe individual and the associated object in combination.
 4. The methodof claim 1, further comprising: altering a selected color on the displayscreen upon the occurrence of a body motion exceeding said motionlimits.
 5. The method of claim 1, said mounting the multiple inertialsensors to the body comprising attaching said sensors to at least onebody appliance worn by the subject, the sensors and said at least oneappliance having corresponding mating structure by which a said sensormay be uniformly and repeatably attached with the same orientation tothe appliance.
 6. The method of claim 1, said existing motion data beinguser-selectable from a database of existing motion data.
 7. The methodof claim 1, said sensor data comprising linear motion, linear velocity,rotational motion, and rotational velocity, in three dimensions, foreach said sensor.
 8. The method of claim 1, further comprising:communicating motion related instructions to the subject; saidcomputer-based motion analysis system comprising means for communicatingsaid motion related instructions to the subject.
 9. The method of claim8, further comprising: communicating motion related performance reportsto the subject; said computer-based motion analysis system comprisingmeans for communicating motion related performance reports to saidsubject.
 10. The method of claim 2, said computer-based motion analysissystem comprising means for communicating said regime of trainingexercises to the subject.
 11. The method of claim 1, comprisingdisplaying said motion data on the display screen.
 12. The method ofclaim 11, said motion data comprising a time-based graph of selectedsaid performance parameters.
 13. The method of claim 1, comprising:setting range of motion limits for selected body segments of said bodymotion in advance of said monitoring; and generating a first audiofeedback signal upon the occurrence of said body motion conducted withinsaid range of motion limits, and a different audio feedback signal uponthe occurrence of a said body motion exceeding said range of motionlimits.
 14. The method of claim 1, said inertial sensors incorporatingwireless data transmitters, said computer-based motion analysis systemincorporating a wireless data receiver.
 15. The method of claim 1, saidcomputer-based motion analysis system comprising a video cameraconnected to the system; said method comprising: monitoring theexecution of a said body motion with the camera; collecting a videosignal of the body motion; displaying the video signal on the displayscreen concurrently with said animation and said motion data.
 16. Amethod for analysis of a body motion of an animal or human subject,comprising: using a computer-based motion analysis system comprisingmultiple, body mountable, inertial sensors in communication with aprocessing computer connected to a computer-driven display screen, atleast one wearable body appliance configured to accept the attachment ofsaid sensors thereto, and means for communicating motion relatedinstructions and performance parameters to a system operator; attachingthe inertial sensors to a selected animal or human subject using the atleast one wearable body appliance such that the sensors are located attarget areas of the body relating to a body motion of interest;calibrating the inertial sensors for initial alignment and orientationof each respective target area of the body; setting range of motionlimits for selected body segments for said body motion; communicatingsaid motion related instructions to the system operator; monitoring theexecution of a said body motion with the motion analysis system;collecting sensor data from said motion sensors; processing said sensordata so as to generate animation and motion data representing said bodymotion, said animation comprising at least two color coded body segmentswherein one body segment is color coded in a different color than theother body segment; displaying the animation and motion data of the bodymotion on the display screen; displaying on the display screen avisually apparent, rectangular, three dimensional open frame cagerepresenting said motion limits for each said selected body segment,within which said animation of said selected body segment is visible;comparing the generated motion data to said motion limits and signalingthe system operator when said limits are exceeded; comparing thegenerated motion data to existing motion data selected from a computerdatabase of exiting motion data, and calculating said performanceparameters there from; communicating said performance parameters to thesystem operator.
 17. The method of claim 16, comprising: prescribing aregime of training exercises selected from a pre-defined list ofexercises where each exercise is associated with at least one saidperformance parameter, and the order and amount of each exercise of theprescribed regime is associated with the relative levels of saidperformance parameters; and communicating the regime of trainingexercises to the system operator.
 18. The method of claim 16,comprising: associating the generated said motion data with the subjectand the date of collection and saving it to the computer database ofexisting motion data.